1. Field of the Invention
The invention relates to a method for determining the position of a workpiece in an NC-controlled machine comprising at least one center point and a computing unit, wherein the workpiece is fixed and the position of at least one point of the workpiece is ascertained by at least one measuring device. The invention also relates to an apparatus that is provided with a movable machine table, on which at least one tailstock is mounted and which is adjustable in relation to the machine table, and with an arithmetic unit for carrying out such a method.
2. Description of the Prior Art
When machining workpieces in NC-controlled machines, both before and during machining the workpieces must have a precise position with respect to the grinding wheel. The workpieces to be machined have tolerances within a series, and these must be taken into consideration at the time of positioning. Separate measuring apparatus are used for this. These measuring apparatus are arranged on the machine and are used to determine the position of the workpiece. This measuring operation is complicated and expensive, since the measuring apparatus has to be re-aligned with respect to the workpieces in each case. If two surfaces must be measured on the workpiece, for example, the measuring apparatus must be brought into two different measuring positions. Hence, a method of this type is time consuming and therefore expensive. The capacity of the NC-controlled machine can consequently not be fully utilized. In addition, it frequently causes problems to be able to position the measuring apparatus on the machine at all.
An object of the present invention to provide a method and an apparatus which determines the position of the workpiece within the shortest time and in the simplest manner, even in those machines in which only a small installation space is available for a measuring apparatus.